package com.yanxinim.cn.util;

import android.content.Context;
import android.content.pm.PackageManager;

/**
 */
@SuppressWarnings("all")
public final class VersionUtil {
    /**
     * https://stackoverflow.com/questions/4616095/how-to-get-the-build-version-number-of-your-android-application
     * 直接BuildConfig.VERSION_NAME就可以，
     */
    public static String getAppVersionName(Context context) {
        try {
            return context.getPackageManager().getPackageInfo(context.getPackageName(), 0).versionName;
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
        return "0";
    }

    /**
     * https://stackoverflow.com/questions/6701948/efficient-way-to-compare-version-strings-in-java
     * <p>
     * Compares two version strings.
     * <p>
     * Use this instead of String.compareTo() for a non-lexicographical
     * comparison that works for version strings. e.g. "1.10".compareTo("1.6").
     *
     * @param str1 a string of ordinal numbers separated by decimal points.
     * @param str2 a string of ordinal numbers separated by decimal points.
     * @return The result is a negative integer if str1 is _numerically_ less than str2.
     * The result is a positive integer if str1 is _numerically_ greater than str2.
     * The result is zero if the strings are _numerically_ equal.
     * @note It does not work if "1.10" is supposed to be equal to "1.10.0".
     */
    @SuppressWarnings("All")
    public static int compare(String str1, String str2) {
        String[] vals1 = str1.split("\\.");
        String[] vals2 = str2.split("\\.");
        int i = 0;
        // set index to first non-equal ordinal or length of shortest version string
        while (i < vals1.length && i < vals2.length && vals1[i].equals(vals2[i])) {
            i++;
        }
        // compare first non-equal ordinal number
        if (i < vals1.length && i < vals2.length) {
            int diff = Integer.valueOf(vals1[i]).compareTo(Integer.valueOf(vals2[i]));
            return Integer.signum(diff);
        }
        // the strings are equal or one string is a substring of the other
        // e.g. "1.2.3" = "1.2.3" or "1.2.3" < "1.2.3.4"
        return Integer.signum(vals1.length - vals2.length);
    }
}